Sure, one late night might make you groggy, but here’s something we weren’t expecting.

According to a study published in Biological Rhythm Research, when a group of football players reduced the number of hours they slept, their physical performance — including peak strength and reaction times — went down after just one late night.

On the other hand, caffeine was shown to not only improve reaction times but also improve the athletes’ strength during workouts.

That tells us two things:

1. If you’re an athlete or have a job that depends on you being in top physical shape, losing sleep at night could hurt your career more than you’ve ever realized.

2. Caffeine can have surprising benefits for physical performance beyond the usual heightened awareness and energy levels.